package test;

import java.util.Scanner;
// 1. 让用户输入圆半径，计算圆的周长和面积，并打印输出
public class Demo1 {
    public static  final float PI= 3.14f;
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        System.out.println("请输入圆的半径");
        float semi=sc.nextFloat();
        float perimeter =semi*2*PI;
        float area =semi*semi*PI;
        System.out.println("周长为:"+perimeter);
        System.out.println("面积为:"+area);

    }
}
